WIRELESS COMMUNICATION APPARATUS

• US 20100056069A1
• Filed: 03/20/2009
• Published: 03/04/2010
• Est. Priority Date: 08/27/2008
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Takagi, Masahiro, Toshimitsu, Kiyoshi
• Application Number:
  US12/408,487
• Publication Number:
  US 20100056069A1
• Time in Patent Office: Days
• US Class Current: 455/75
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04L 2027/0018 Arrangements at the transmitter end
• CPC Class Codes: H04L 2027/0022 using the carrier of the associated receiver of a transceiver
• CPC Class Codes: H04L 27/0014 Carrier regulation of chaotic carriers H04L27/001; for multicarrier receivers H04L27/2657
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 27/2657 Carrier synchronisation

Abstract

A wireless communication apparatus receives a radio signal, compensates a frequency offset of received radio signal, stores, in a memory, a frequency offset of the received radio signal which includes an address used as a destination of a transmission signal, compensates a frequency of the transmission signal having the address as the destination by using the frequency offset stored in the memory, and transmits the transmission signal whose frequency is compensated.

Claims

1. A wireless communication apparatus comprising:

a reception unit configured to receive a radio signal;

a reception frequency compensation unit configured to compensate, every time the radio signal is received by the reception unit, a frequency offset of the radio signal;

a control unit configured to store, in a memory, the frequency offset of the radio signal which includes an address used as a destination of a transmission signal;

a transmission frequency compensation unit configured to compensate a frequency of the transmission signal having the address as the destination by using the frequency offset stored in the memory; and

a transmission unit configured to transmit the transmission signal whose frequency is compensated by the transmission frequency compensation unit.

2. The apparatus according to claim 1, wherein the control unit stores, in the memory, the frequency offset of the radio signal including the address as the destination of the transmission signal to be subjected to one of spatial multiplexing and orthogonal frequency division multiple access.

3. The apparatus according to claim 1, wherein the control unit stores, in the memory, the frequency offset of the radio signal including, as a source address, the address which coincides with the destination of the transmission signal.

4. The apparatus according to claim 1, wherein the control unit stores, in the memory, the frequency offset of the radio signal which further includes information indicating a period during which transmission of the transmission signal is permitted, and

the transmission frequency compensation unit compensates the frequency of the transmission signal transmitted during the period by using the frequency offset stored in the memory.

5. The apparatus according to claim 1, wherein the control unit stores, in the memory, the frequency offset of the radio signal further including an identifier indicating a base station.

6. The apparatus according to claim 1, further comprising:

an oscillator to supply a frequency signal to the reception unit and the transmission unit, and wherein

the transmission frequency compensation unit compensates an oscillator-frequency of the oscillator and compensates the frequency of the transmission signal by using a remaining offset obtained by subtracting a compensation amount of the oscillator-frequency from the frequency offset stored in the memory.

7. The apparatus according to claim 1, wherein when the radio signal which is received by the reception unit after the transmission signal is transmitted by the transmission unit, includes, as a source address, the address which coincides with the destination, and includes a feedback offset, the control unit adjusts the frequency offset stored in the memory by using the feedback offset.

8. The apparatus according to claim 1, wherein

the reception unit receives the radio signal including one of first bit information which permits storing, in the memory, the frequency offset of the radio signal compensated by the reception frequency compensation unit and second bit information for inhibiting the frequency offset from being stored in the memory, and

the control unit (a) stores, in the memory, the frequency offset of the radio signal which includes, as a source address, the address coinciding with the destination and includes the first bit information, and

(b) does not store, in the memory, the frequency offset of the radio signal which includes, as the source address, the address coinciding with the destination and includes the second bit information.

9. The apparatus according to claim 8, wherein when the radio signal which is received by the reception unit after the transmission signal is transmitted by the transmission unit, includes, as a source address, the address which coincides with the destination, and includes the second bit information and a feedback offset, the control unit adjusts the frequency offset stored in the memory by using the feedback offset without storing, in the memory, the frequency offset of the radio signal.

10. The apparatus according to claim 1, wherein

the memory stores a plurality of frequency offsets corresponding to a plurality of destination addresses respectively, and

the transmission frequency compensation unit compensates the frequency of the transmission signal by using the frequency offset, of the frequency offsets stored in the memory, which corresponds to a destination address of the transmission signal.

15. The method according to claim 1, wherein storing stores, in the memory, the frequency offset of the received radio signal which further includes an identifier indicating a base station.

17. The method according to claim 1, further comprising:

receiving, after the transmission signal is transmitted, a response signal responding to the transmission signal and including a feed back offset;

adjusting the frequency offset stored in the memory by using the feedback offset included in the response signal.

11. A wireless communication method comprising:

receiving a radio signal;

compensating a frequency offset of received radio signal;

storing, in a memory, a frequency offset of the received radio signal which includes an address used as a destination of a transmission signal;

compensating a frequency of the transmission signal having the address as the destination by using the frequency offset stored in the memory; and

transmitting the transmission signal whose frequency is compensated.

12. The method according to claim 11, wherein storing stores, in the memory, the frequency offset of the received radio signal including the address as the destination of the transmission signal to be subjected to one of spatial multiplexing and orthogonal frequency division multiple access.

13. The method according to claim 11, wherein storing stores, in the memory, the frequency offset of the received radio signal including, as a source address, the address which coincides with the destination of the transmission signal.

14. The method according to claim 11, wherein storing stores, in the memory, the frequency offset of the received radio signal which further includes information indicating a period during which transmission of the transmission signal is permitted, and

compensating the frequency of the transmission signal compensates the frequency of the transmission signal transmitted during the period by using the frequency offset stored in the memory.

16. The method according to claim 11, wherein

compensating the frequency of the transmission signal includes

compensating an oscillator-frequency of a oscillator to supply a frequency signal used to receive the radio signal and transmit the transmission signal;

and

compensating the frequency of the transmission signal by using a remaining offset obtained by subtracting a compensation amount of the oscillator-frequency from the frequency offset stored in the memory.

18. The method according to claim 11, wherein

receiving receives the radio signal including one of first bit information which permits storing, in the memory, the frequency offset of the radio signal compensated and second bit information for inhibiting the frequency offset from being stored in the memory, and

storing (a) stores, in the memory, the frequency offset of the radio signal which includes, as a source address, the address coinciding with the destination and includes the first bit information, and (b) does not store, in the memory, the frequency offset of the radio signal which includes, as the source address, the address coinciding with the destination and includes the second bit information.